1. Field of the Invention
The present invention relates to a liquid crystal display device (a semiconductor device) which comprises a display portion for displaying information such as images and text, and to a manufacturing method of the same. More particularly, the invention relates to a configuration of a driver circuit for transmitting a signal to each pixel of a pixel region forming a display portion, and to manufacturing and mounting methods of the same. Further, the invention relates to a liquid crystal display device (a semiconductor device) comprising a region in which semiconductor elements such as thin film transistors are arranged in matrix, and more specifically, to a configuration of a circuit formed in the periphery of this region, and manufacturing and mounting methods of the same.
2. Description of the Related Art
Among liquid crystal display devices comprising a liquid crystal layer, used is an active matrix display device comprising a pixel region in which thin film transistors (TFTs) are arranged in matrix for displaying information such as images. Such a display device has the advantage of reduced weight and thickness, therefore, it is used for various types of electronic apparatuses such as a notebook personal computer, a mobile computer, a mobile phone, and a liquid crystal television.
A technology for forming a channel portion by using an amorphous semiconductor provides improved productivity, since the amorphous semiconductor is capable of being formed on a relatively inexpensive and large sized substrate. However, in the case where a channel portion is formed of an amorphous semiconductor, the field effect mobility of a thin film transistor is approximately 1 cm2/Vsec at most. Such a thin film transistor can be used as a switching TFT provided in a pixel region, but can not be used as an element forming a driver circuit which is required to operate at a high rate.
Accordingly, a driver circuit is mounted in the periphery of the pixel region by TAB (TCP) or COG by means of an IC chip formed on a single crystalline silicon substrate. In TAB, a driver IC having a bump in a pad portion is connected with alloy to a film circuit in which a circuit is formed of polyimide with copper foil by photolithography and then plated. The driver IC is sealed thereafter with resin and packaged. In COG, an IC chip is mounted on a substrate of a display device so as to be electrically connected to a wiring pattern which has been formed on the substrate.
When mounting a driver circuit by COG, a plurality of TFTs are formed of a non-monocrystalline semiconductor material on a substrate such as a glass substrate and a quartz substrate, and then divided into strip-shaped circuits. Afterwards, the strip-shaped driver circuits are mounted on another substrate (see Patent Document 1, for example).
[Patent Document 1] Japanese Patent Laid-Open No. H11-160734